The Mighty from air purifier stalwarts Coway might have the best bang for your buck when it comes to air purifiers. At under $200, the Mighty can clean a 361-square-foot room, exchanging the air the recommended 4.8 times per hour. Note that this is based on running the Mighty at its highest and loudest setting at 53 decibels. And, as I’ve written before, you most likely won’t want that kind of white noise 24/7, so I suggest fitting the Mighty in a room around 200 square feet or smaller to run it at a quieter setting while still benefiting from a high air exchange rate. It has an on/off button for the ionizer and a timer activation/deactivation feature that will power off after 1, 4, or 8 hours, along with Eco Mode that turns off the fan if no pollution is detected for 30 minutes.

The Mighty has a built-in air sensor and air quality light that shines blue for clean air, dark purple for polluted air, and red for highly polluted. This is Coway’s color system, and I found it confusing as the colors don’t line up with the US air quality index standards of green for good, red for unhealthy, and purple for very unhealthy. It is the air sensor that enables the Mighty to automatically adjust its fan speed. At just under a foot and a half tall and 12 pounds, the box-like Mighty feels lighter than that with its easy-to-grab back handle. I pulled off the front cover to reveal the Mighty’s three filters: a HEPA, a deodorizing filter, and the prefilter. The Mighty also needs to sit about 8 inches from the wall or furniture. And while I liked the simple design of the Mighty, its glossy white plastic finish attracts pet hair in that clingy, staticlike way. It isn’t compatible with Google Home or Amazon’s Alexa, nor does it have a remote or app. Still, for the price, the Mighty is an excellent air purifier for small rooms.

The Dyson HushJet uses new electrostatic filter technology to extend filter life up to five years, and for under $300, this app-compatible air purifier might be the air purifier of the future.

The HushJet has an almost Dune sandworm-like spout that projects clean air straight up. At a 1 ½ feet, the 7-pound cylinder can capture and clean the air in a small, under-200-square-foot-sized room. I put the HushJet on the nightstand next to my bed in my small bedroom. And while it’s called the HushJet, at its highest fan setting, it was registering upper 80s and low 90 decibels on my consumer Toptes RA-5018 sound level meter. Unlike Dyson’s other air purifiers, the HushJet doesn’t use a HEPA—it’s an electrostatic filter. Dyson’s air purifiers usually show up on the California Air Resources Board (CARB) list of CARB-certified air purifiers. For an air purifier to receive CARB certification means that the purifier meets standards of electronic and ozone safety. As of this writing, the HushJet Purifier Compact HJ10 is not on the list, though the list is constantly being updated.

I was excited to try this air purifier/furniture hybrid complete with a mood light and phone charger. At first I wanted to place it next to my bed, but as I read the fine print, I saw the SwitchBot Air Purifier Table needs 12 inches of clearance on three sides. Air purifiers, especially cylindrical air purifiers, need unobstructed airflow. The SwitchBot Air Purifier Table allows for one side to be 1 inch away from a wall, but not curtains. Those kinds of placement restrictions keep the side table from being a side table. The only unobstructed, free-standing table I have in my home is my dining room table. In some ways, I’m waiting for the large-room air purifier dining room table to be introduced to really be a fully functional air purifier table.

If you don’t mind a small table that can stand against the wall, then the air purifier table might work for a small entryway or bathroom. It has both a HEPA filter for PM 2.5 and an activated carbon filter to remove odor and volatile organic compounds (VOCs). There’s also an ambient 10-color light that illuminates from below the tabletop. At its highest setting, the purifier measured around 70 dB on my consumer Toptes RA-5018 sound level meter—loud enough to be noticeable in the background. And while the SwitchBot table can exchange the air in a 260-square-foot room five times an hour, that would be at its highest, loudest setting. The ideal size for the SwitchBot would be more like a 100-square-foot space, such as a mud room, entryway, or bathroom.

The Mini Restful is part of Blueair’s Sleep Collection, and is also the smallest—or close to the smallest—air purifier I’ve tested. Blueair claims that the Mini Restful can effectively clean the air at the CDC-recommended five air changes an hour in a 140-square-foot space, but that would be at its highest setting. My consumer Toptes RA-5018 sound level meter registered 60 dB—around the sound of a conversation. No one is sleeping with that noise. Instead, the Mini Restful is quiet on its lower setting. At that setting, however, the Mini Restful could complete the recommended air exchanges in the space the size of one of those sleeper pods found at capsule hotels.

As for the sunrise alarm, it was easy to program through Blueair’s app. The Mini Restful has nine sounds to choose from, like Midnight Rain, Happy Rise, and Mantra Breeze. I set the alarm to the sound of Nordic Flow, a blend of light harp strings and birds chirping. The alarm is designed to begin the subtle sunrise light anywhere from 15 minutes to 30 minutes before the selected wake-up alarm time. I set the alarm to 5 am and was woken up by the light at 4:45 am. I may just be more sensitive to light, but I needed to move the Mini Restful to my hallway, where it successfully woke me up to the pleasant sounds of Nordic Flow.

IQAir released its latest air purifier, the Atem Earth, in early September. It’s a departure from the brand’s plastic-encased air purifiers and is the first wood exterior model WIRED has tested. IQAir claims that the 2-foot-tall cylindrical Atem Earth uses five times less plastic than conventional air purifiers. The Atem is encased in sustainably sourced, naturally finished beech wood. It comes with a thick faux leather handle that makes moving the 17-pound purifier easy to do. Like other purifiers by IQAir, it pairs with IQAir’s comprehensive air quality app, which also works as the device’s remote. IQAir’s app continues to be the best we’ve tested. Other new features included the AQI (Air Quality Index) indicator light rings on the control panel that show both indoor and outdoor air. IQAir uses the US AQI standard color scale (though there is an option to switch to the Chinese AQI scale): green for good, yellow for moderate, orange for unhealthy for sensitive groups, red for unhealthy, purple for very unhealthy, and blinking purple for hazardous. The built-in indoor PM 2.5 sensor adjusts the fan speed when on smart mode. The outdoor air AQI can be set to a local monitor or your own AQI Outdoor Air Monitor.

The Atem Earth pulls air into its vortex through the air inlet located around the lower part of its body—the reason the wooden exterior has latticelike cutout vents. The proprietary HyperHEPA filter captures PM 2.5, while the activated carbon filter removes VOCs (volatile organic compounds), odors, and vapors from the air. The wood exterior changed the entire vibe of the purifier, and I hope this is the beginning of the trend away from plastic. The beech wood enabled the Atem Earth to blend into the room. Clean air is blown out through the air outlet atop the purifier through vents that encircle the control panel. It has a filter indicator light and a panel lock, which is especially useful for cat owners. One drawback is seeing the indicator lights on the flat top surface. If I wasn’t angled above the purifier, I couldn’t see the lights. The other issue, and I’ve had this with other IQAir models, is that they can be loud at their highest fan speed. My consumer decibel reader was reading over 80 decibels when the Atem Earth was at its highest fan speed.

The thousand-dollar price tag is steep, but like all IQAir air purifiers, this is a long-term investment, and the fact that this model is environmentally friendly makes it worth considering. The combination of a 10-year warranty coupled with a 25-year replacement and repairability guarantee means you’re buying an air purifier that will last a quarter of a century. I’ve replaced the control panel on another IQAir air purifier and it was easy to do. I also like the real-time filter life expectancy meter on the app. WIRED has tested half a dozen IQAir air purifiers, and it’s been our experience that IQAir filters last a long time before changing.

The Coway Airmega ProX is the monolith your high-ceiling home needs. If you’re living in an A-frame, double-height ceiling loft, or any home with a ceiling higher than 8 feet, the Coway Aimega ProX is for you. The ProX gives off a TARS robot from Interstellar meets giant stereo speaker vibe. It’s blend-into-the-room-mocha beige and can clean the air four times per hour in a 1,000-square-foot space when running at its highest setting. And even at its highest and therefore loudest setting, it hovers around 50 decibels, slightly louder than the sound of falling rain—making it one of the quieter large tower air purifiers I’ve tested. It also has a control panel lock that is a plus for parents and cat owners alike.

The control panel features Coway’s real-time slightly confusing air quality indicator light: blue for good, green for moderate, yellow for unhealthy, and red for very unhealthy. There’s also the PM 2.5 number that is sometimes difficult to read depending on the angle. There are three customizable airflow speeds. I prefer to leave it on auto mode. Its built-in sensor adjusted the fan speed depending on my indoor air quality and was in sync with my air quality monitors. And while it wasn’t app-enabled, the ProX was able to adjust to clean my air efficiently and quietly. I was also able to move the 50-pound ProX using its hidden handles and built-in lockable wheels. And while the ProX is one of the more expensive models I’ve tested, the five-year warranty puts it in the wise investment category.

Coway has yet to make a bad air purifier, and the Airmega 400S is another banger from the air purifier innovators. The 400S checks all the boxes when it comes to features. It has a reliable auto mode that adjusts the fan speed according to the air quality using its built-in air quality sensor. It also has a timer to schedule one, four, or eight hours of running time. And while it has a serviceable app, its built-in air sensor and auto-adjust fan keep me from having to micromanage settings. The question is, can this air purifier do the job without me pushing buttons or checking the indoor air quality, and do it quietly? With the Airmega 400S, the answer is yes.

The 400S has an easy-to-see, real-time air quality sensor indicator light that glows blue/green for good, green/yellow for moderate, yellow/orange for unhealthy, and orange/red for very unhealthy. And as it is on the larger side, the 400S is quiet. It’s easy to forget it’s on, and it doesn’t call attention to itself on its highest setting. And perhaps my favorite feature is the 400S’s filter indicator lights. It doesn’t just let me know when to change the HEPA or activated charcoal filter, but it will also let me know when to wash the prefilter. I can’t think of another air purifier that does that. And if you want your air purifiers to run well, keeping that prefilter clean is an easy bit of essential maintenance.

The AirDoctor 5500i is the latest purifier from the AirDoctor line and the second tower model I’ve used. I’ve used IQAir’s standard GC MultiGas model for years. Because of their power, tower models tend to be loud at their highest settings, so I was pleasantly surprised by the 5500i’s quiet hum. It captures both fine particulates—like mold spores—with its HEPA filters, and gases with its dual-action/carbon volatile organic compound (VOC) trap filters. The 5500i can exchange the air four times an hour in a 1,000-square-foot space, around the size of my New York apartment. And the purifier has an alert to let me know when it is time to change the filter.

It’s the quietest and largest AirDoctor air purifier yet. It has a built-in sensor that has kept up with my cooking, turning its air quality indicator light red and automatically adjusting the fan speed to the highest setting. This also happens when construction in my building goes into overdrive. Yet it is quieter than the smaller AirDoctor 2000, the same model that once woke me up in the middle of the night. The 5500i caps at 50 decibels, quieter than a household refrigerator. It weighs 33 pounds, and I needed help getting the shipping box up the three flights of stairs to my apartment. Moving it around my apartment only took a slight nudge of the hand, as it has hidden casters that let it glide easily on my hardwood floor. It connects to the AirDoctor app and can be controlled remotely. And with AirDoctor’s thousand-dollar price tag, the disappointing one-year warranty seems short for the investment. While IQAir’s GC Multigas costs $350 more than the 5500i, it offers a 10-year warranty option. As much as I liked AirDoctor’s performance, I might buy the more expensive and comparable IQAir model for the warranty alone. Air purifiers are long-term investments.

The Rabbit Air is a sleek, disappears-in-a-room air purifier that punches above its weight. Its low price makes it one of the better investments, especially with its five-year warranty. It has both a HEPA filter to trap common allergens like dust and pollen, plus that dangerous invisible PM 2.5, like in wildfire smoke. It’s also got an activated charcoal carbon filter to capture VOCs and odors. It also has a negative ion generator that basically gives air molecules a static charge, making them easier to capture.

The BioGS 2.0 is able to clean 550 square feet at two air exchanges per hour and 275 square feet at four air exchanges per hour. I could clean my entire 1,000-square-foot apartment with two Rabbit Air BioGS 2.0s, and as the air purifiers are under $400 each, they’re some of the more affordable options on the market. The Rabbit’s built-in sensors adjust fan speeds, and the unit’s control panel illuminates in low-light settings. It also has a remote. I was disappointed that the BioGS 2.0 isn’t compatible with the Rabbit Air app, nor can it work with Amazon’s Alexa or Google Assistant like other Rabbit Air models. Still, because of its cost, quiet operation, ability, and style, this is one of my favorite air purifiers.

Blueair makes a larger room 3-in-1 air purifier and a small room 3-in-1. I gave Blueair’s small-room model a test drive in my 200-square-foot bedroom. At a little under 2 feet tall, the 3-in-1 has more features than you usually find in an air purifier. It oscillates and has a built-in heating and cooling function. Blueair’s app is easy to use and I preferred controlling the purifier via the app rather than the actual control panel. The panel did not always illuminate when pressed, making pushing the buttons difficult. There are also more options on the app, like controlling the oscillation speed and angle. Blueair uses both mechanical—as in HEPA filtration—and electrostatic technology to capture pollutants in the air. Its CARB certification is listed as electronic, unlike HEPA-only air purifiers that are listed as mechanical.

The Blueair also has an air quality index indicator light that responds to the purifier’s built-in sensor to measure PM 2.5. The easy-to-miss sliver of light glows blue for excellent, green for good, yellow for moderate, orange for polluted, and red for very polluted. It has a control panel lock and filter change indicator light. I also appreciate the cloth handle that makes moving the Blueair easy. For its small size, I found the Blueair 3-in-1 to be louder than expected at full fan. And while Blueair says it’s 53 decibels at its highest setting, my non-calibrated consumer Tadeto decibel reader had it at 85 dB at full fan. I mention this because usually, my decibel reader is within 10 points of the manufacturer’s decibel numbers.

I’ve been using the IQAir GC for the past five years and was excited to give the newer air-sensor and app-enabled IQAir CG XE model a test run. In the past I’ve used my GC tower in the space between my kitchen and dining room, turning it on the highest setting whenever I used my gas stove. Both the GC and CG XE clean the air of volatile organic compounds and PM 2.5, those invisible particles that can enter the bloodstream and cause health issues. And like the Atem X, the GC Series XE comes with its own certificate of performance and a 10-year warranty. The Swiss-made air purifier is a tower model that needs to be at least a foot away from any wall. And while it’s heavy at 55 pounds, the casters let me roll it around my house. I also appreciate that the air sensor’s indicator light is in accordance with US AQI colors. And the built-in sensor and IQAir app make the CG XE easy to use. I used to have to manually control the fan speed on my older GC, but in auto setting, the CG XE knows what to do. I also find IQAir app to have one of the most intuitive user experiences I’ve tested.

And like the Atem X, these Swiss-made air units are top of the line for a reason, but the 10-year warranty makes IQAir’s purifiers a wise investment. And unlike the Atem X, the CG XE can also capture toxic gases and vapors. It is also one of the largest models I’ve tested, and at its highest setting it can clean 275 cubic feet per minute, or CFM. On auto mode, the fan speeds adjust. It can clean the air of a large space with multiple air exchanges in an hour. I’ve been using the CG XE in the main room of an A-frame cabin with double-height ceilings (around 3,000 cubic feet) for the past two months, and it has kept my indoor air quality healthy. But with great power comes great noise. At its highest setting, the CG XE runs at a loud 68 decibels—that’s just 2 decibels shy of the sound of a consumer vacuum cleaner, though it’s quiet at its lower settings. At $1,400, this workhorse isn’t cheap, but it’s an investment that’s built to last.

The Airdog X5 is the first washable filter air purifier I’ve tested. And while it doesn’t use a HEPA, it is California Air Resources Board certified. CARB lists it as electronic filtration instead of a HEPA filter; that would be listed as mechanical. As I’ve written before, if an air purifier isn’t CARB-certified, don’t buy it. I tested the Airdog in a large room. I even received the limited-edition pet plate. That is exactly what it sounds like—a plate that fits over the Airdog meant for a cat to perch on. Neither of my cats took to it.

The Airdog has a responsive built-in sensor that was in sync with my other air quality monitors. And its electronic air filters, by way of their patented TPA technology, charge particles and then capture them. The best way I can describe it: Imagine that the PM 2.5 are mosquitoes and the Airdog is like an old-time mosquito zapper. It works a little like that, and if the filter gets dirty enough, it will make zap sounds. The manual mentions that it’s time to wash the filter when you hear those zaps. The prefilter collected visible debris, including cat hair. And there is something to be said about not having to buy expensive replacement filters. I hope Airdog’s next pet model has a built-in cat tree.

This is the second Rabbit air purifier I’ve tested, and again I am impressed by its quiet fan. Even on its highest Turbo setting, it’s quieter than other units I’ve tested at their maximum. And like the Rabbit Air BioGS 2.0 above, it doesn’t stand out as an unsightly appliance. Add to that the A3’s easy-to-remove customizable magnetic front panel and it goes from air purifier to aesthetically pleasing statement piece. If you decide to use the included wall mount hardware, the A3 can be the art your home gallery needed. I tested the A3 with the soon-to-be-released iconic Hello Kitty panel. There’s also Peanuts, along with other images like Katsushika Hokusai’s The Great Wave and van Gogh’s Starry Night, to name a few.

There’s a lot going for the A3; it has an easy-to-use control panel and RabbitAir app, air quality indicator, filter indicator light, ion generator that can be turned on and off, adjustable auto mode that can be set from low to high sensitivity, 24/7 support, and a five-year warranty. But all of this comes with a higher price tag at just under $800. The 3A also has a mood light setting. When I first turned on the MinusA3, I didn’t know why my air was going from bad to good within a minute until I realized it was a mood light feature for aesthetics. The light beams come from the top of the A3 panel. And while the cycling mood light is adjustable through the app, it was confusing. My first thought when any air purifier beams out purple: My indoor air is very unhealthy. The light sensor is easy enough to turn off, but I wish there were a light setting that could be synced up with the air quality indicator. Also, the control panel or interface at the top turns off when you’re not touching it, and as I have yet to remember which button does what, it creates an extra step for the user.

As I mentioned, it’s quiet—an almost inaudible 22 decibels at its whisper setting. Another unique element of the 3A is the customizable filters. I was sent the new anniversary-issued, green tea-infused filter, but there’s also a toxin absorber, germ defense, odor remover, and one for pet dander. These are in addition to the prefilter, the medium filter, the activated carbon filter, and HEPA filter. And while there is yet to be any research or scientific studies to back up the benefits and efficacy of a green tea-infused filter, I’d like to think that the same health benefits one gets from drinking green tea could somehow transfer to breathing through a green tea filter. The RabbitAir 3A Ultra Quiet Air Purifier is a luxury, both in looks and in function. The Artist Series can do four air exchanges in a 515 square foot room, so consider using the 3A in a room about 250 square feet to run it at a lower and quieter setting. It reminds me of the ultra-modern Atem X (above) from IQAir, a high-end model that looks as good as it works. I could see the 3A with Snoopy panel hanging in a child’s room, blending into the interior.